Main Findings
In this retrospective study, the results demonstrated long post-thawed culture could be causing a significant increase in the IR, CPR, MPR and LBR. Then transferred embryos with more blastomere growth had a higher IR, CPR, MPR and LBR. The study also indicated that the neonatal characteristics between L and S groups were similar, and the twin group had a lower average gestational age and birthweight as well as a higher cesarean section rate, preterm labor rate and low birthweight rate than the singleton group.